Method of and means for receiving telegraphic signals



A. JIPP Nov. 25, 1930.

METHODOF AND MEANS FOR RECEIVING TELEGRAPHIU SIGNALS Filed NOV. 30, 1928Ill wuwm RM moeutoz AUGUST JIPP' @5 WM?! (94].. 44M

Patented Nov. 25, 1930 UNITED, STATES,

AUGUST JIrr, OF BERLIN-SPANDAU, GERMANY, Assre'noa T0 simvrnns & HALSKE,AKTIENGESELLSGHAFT, or sInMnnss'rAnT,nneaenntin, GE MA Y, A coarena vTION 0F GERMANY METHOD or AND MEANS r012. ancnivrnemnrnenlernio srenALsApplication filed November 30, 1928, Serial No. 322,624, andin Germany August6,1927.' i

nalling that the incoming signals are often mixed with disturbances, forinstance, of atmospherlc orlgin and nature, whereby the received signalsare often rendered unintelligible.

around 1.6 times the dot frequency utilized in telegraphic signalling,can be eliminated by the aid of filter circuits or parallel con-f densers.

According to this invention these disturb-j ances (including thedotcurrents) down to about 1.6 timesthe dash frequency, i. e., to

' about 0.5 times the, dot frequency, are to be eliminated.

The invention is based dashes, and that the characteristic distinctionbetween the si ns inheres only insuch suppressionai. e., the dashes andspaces, but not in the uninterrupted alternating current.

are made more readily readable.

This unchanging pattern or stencil consist-' mg of the alternatmgcurrent, accordlngto the invention, is locally added again to the V lumor of a revolving machine adapted to 45 text, freed from disturbancesand dots; All

that isnecessary is to know the frequency be used for thesynchronization of a pendugenerate an alternating current patternt'ashlon wlth accuracy, free'from disturbance.

Finally the generated alternating current is combined with the incomingcurrents which quencies.

have been freedtrom dot and stray ire- Application filed in Germany,August 6, L

It is also known that disturbances of relatively high frequency, say,down to upon the fact that p the Morse signals chiefly used in radiowork consist eta continuous alternating current (Fig. 1, curve I) inwhich certain waves are") suppressed for the formation of dots and I isbrought toconjointlyfact with the incomlike.

The accompanying'drawing shows an ex emplification er the, basic idea ofthe invention for'better understanding. the drawing Fig.1 shows theshape ofthe current in the diiierent parts of the circuit arrangementand; the desired resultant com positiontoact asth.e",. ,final currentupon recorder apparatus and Fig. .2 a circuit arrangement are nymg ut,tliesteps shown in Fig.1. fl"

ferrin to Fig. ,1 the incoming current,

after, rectifieation, "has the shape off curve I,

the" dot frequencies suppressed in si nalling beinghere shown bydottedlines @urve II of Fig. ,1 shows the form of this 'currentaiiterhavingpassed'a filter circuit in which all stray anddot frequencies areeliminateiwith 1 the latter being indicated by the dash lines.

1: shapeof the current in theoscillation "circuit orin the alarmingtuned tothe'dot frequency and connected in parallel relation to fthefilter circuit is Shem in byfcurv'e III.

The ,feeblyidampe'd circuitis impnl sed every of asynchronous, motor anda eonmet disk, a"

afdotffsignalcomes in] This current is V made togproduce, for instance,by the, aid

'm-Em OFFICE" new current of the stal frequency, but of sharplyrectangular form as shown in curve IV. The current shown'in graphIV'then lngcurrent II whosepath is closed by way filter upon arecordingdevice orthe of the Currents and IV combinedly result in a currenthavingashape as jshown in curve It in this current, say',"bycurrent-limit ng suppress the dot and stray frequencies,

on the other hand, an oscillation circuit In which is tuned to the dotfrequency. Connected with said oscillation circuit 10 is the stator of asynchronous motor m whose rotor drives a contact disk 8. The latter,owing to alternate change of polarity of two batteries 2) producessharply outlined rectangular current impulses of dot frequency in acircuit brought to recording apparatus a, and these current impulses arecombined with the incoming currents having passed through the filter andbeing of dash frequency, thus resulting in signals of the desired form.

What is claimed is 1. The method of receiving signals which includesfiltering out from the incoming signal currents dot frequency and strayfrequency currents, and combining the remainder of the incoming signalcurrents with a locally generated alternating current of dot frequencyand predetermined shape whose frequency is made to depend upon the dotfrequency of the incoming signal.

2. The method of receiving radio telegraphic signals consisting of acarrier modulated by dots of a predetermined dot frequency and dashesobtained by the suppression of dot frequency energy which includesrectifying the incoming signal, filtering from the rectified signal dotand stray frequency currents, generating a current of the dot frequencyand of a predetermined shape, and combining the generated current andthe remainder of the incoming rectified signal current.

3. A receiver comprising afilter for filtering from a received rectifiedsignal currents of dot and stray frequencies, a generator for generatingan alternating current, means for combining the generated alternatingcurrent and the currents passed by the filter and means for recordingthe combined currents.

4. The method of receiving radio telegraphic signals consisting of acarrier modulated by dots of a predetermined dot frequency and dashesobtained by suppressing dots, which includes, rectifying the incomingsignal, separating dot and dash frequency energy from the rectifiedenergy, utilizing the separated dot frequency energy to generatelocally, square wave form energy, combining the square wave form energywith the filtered dash frequency energy, limiting the combined energy,and translating the limited energy. 7

In testimony whereof I affix my signature.

AUGUST JIPP.

